JPS6135498B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for measuring the amount of unbalance of wheels mounted on an automobile.

(Prior Art) Conventionally, this type of device, as shown in Japanese Unexamined Patent Publication No. 47-2548, measures the vibration amplitude and vibration amplitude by suspending the axle near the wheels of an automobile with a pick-up and rotating the wheels. Detects the balance position and
Then, a weight of arbitrary known weight is added to this position, the vibration amplitude is measured again, and the true amount of unbalance is determined from the proportional relationship between the difference in vibration amplitude before and after adding the weight and the weight of the weight. There is.

According to this device, it is possible to measure the amount of unbalance without removing the wheels from the vehicle, but since it is affected by the size of the wheels, the type of vehicle, the mounting position of the pick-up, etc., it is difficult to measure the amount of unbalance by actually measuring the weight of the weight to be added. Therefore, there was a problem in that the measurement work was required to be performed many times while gradually changing the temperature, and the measurement work required time and skill.

(Object of the Invention) By the way, in the on-the-car type unbalance measuring device described above, the value of the pick-up output with respect to the amount of wheel unbalance depends on the size of the wheel, the type of vehicle, the mounting condition of the pick-up, etc. Although they vary greatly depending on the conditions (hereinafter referred to as measurement conditions), once the above measurement conditions are fixed, the change in the unbalance amount and the pick-up output have a certain fixed functional relationship, that is, The characteristic curve not only changes along the same characteristic curve, but also maintains a certain order even as the measurement conditions change; in other words, as shown in Figure 2, the variation of the functional relationship due to the measurement conditions is
The present inventor has found that the property is within the area surrounded by the curve H and the curve L, and changes in a form that divides the curve H and the curve L as shown in FIGS. 3 and 4. , I found out. The present invention
It is an object of the present invention to propose a measuring method that can actively utilize such properties to measure the amount of unbalance of wheels mounted on a vehicle with as few measurement operations as possible.

Another object of the present invention is to provide an apparatus for implementing the above measurement method.

(Structure of the Invention) The present invention is characterized by storing a plurality of characteristic curves corresponding to differences in wheels and vehicle types that indicate the relationship between the magnitude of vibration generated during wheel rotation and the correct amount of unbalance. , the difference between the pickup output before and after adding a known amount of weight specified by one of the characteristic curves and the unbalance amount determined based on one of the characteristic curves is the unbalance amount corresponding to this weight. The point is that a characteristic curve representing the amount is selected.

The details of the present invention will be explained below based on illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which reference numeral 3 denotes a pick-up installed between an axle 2 of an automobile (not shown) and the ground, and a drive wheel attached to an electric motor 5. This is to detect the magnitude of vertical vibration caused by unbalance of the tested wheel 1 rotated by the wheel 4.

Reference numeral 7 denotes a flash drive circuit which operates the flash lamp 6 at the bottom dead center of vibration in response to a signal from the pickup 3. Reference numeral 11 denotes a selection circuit configured to access an unbalance amount in a storage circuit 10, which will be described later, based on a pickup signal inputted via the analog-digital exchange circuit 9. Reference numeral 10 denotes the aforementioned memory circuit, which stores the relationship between the unbalance amount and the pickup output under the aforementioned measurement conditions, that is, the relationship between the unbalance amount and the pickup output that varies depending on the measurement conditions as shown in FIG. is investigated in advance, and the output of the pickup 3 is used as an address, and the unbalance amount is stored as data. Reference numeral 12 denotes a process control circuit, which selects the characteristic curve with the smallest increase in unbalance amount relative to the increase in vibration magnitude among the characteristic curves in the first measurement stage, and outputs the first pickup without adding any weight. The selection circuit 11 outputs the weight corresponding to the weight, and based on the second pickup output to which this weight is attached and the first pickup output, characteristic curves are sequentially selected until a discrimination circuit 14 (to be described later) detects a matching state. is configured to do so. 14 is the aforementioned discrimination circuit;
A circuit 13 that detects the coincidence between the difference in the unbalanced amount read out from the pick-up output value and the weight of the first weight added, and displays the unbalanced amount based on the characteristic curve selected at the time of coincidence. is configured to output to .

Next, the operation of the apparatus configured as described above will be explained based on FIG. 6.

In the present invention, first, a mark is placed on the wheel 1 with a wheel yoke or the like in order to easily confirm the position of the unbalanced wheel during rotation. A wheel 1 is lifted from the ground, supported by a pick-up 3, and rotated by an electric motor 5 via a drive wheel 4. The pickup 3 detects the vertical vibration of the axle 2 caused by the rotation of the wheel 1, and sends it to the flash drive circuit 7.
The position where wheel 1 is heavily balanced is the bottom dead center (vertical)
Activate the flash lamp 6 at an appropriate moment (bottom) to check the position of a mark that has been placed in advance so that the rotating wheel 1 can be observed stationary, and after the rotation has stopped, place the mark in the same position as when the flash was operating. When this is done, the area directly above the wheel is where the weight should be attached for balance.

At this point, the process control circuit 12
0 - Select the pick-up output characteristic curve H to find the unbalance amount that matches the output value Y1 of the pick-up 3 obtained from this first measurement. m1H is output to the display circuit 13 and displayed. After attaching the displayed and known weight m1H to the unbalanced position of the wheels found in the above process, the measurement operation is performed again. Selection circuit 11
The determination circuit 1 reads out the unbalance amount m2H from the output value Y2 of the pickup 3 obtained by this measurement operation from the storage circuit 10 and the unbalance amount-pickup output characteristic curve H selected in the above-mentioned process.
Output to 4. The determination circuit 14 compares the weight of the added weight, that is, the total unbalance amount m1H on the characteristic curve H, and the read difference between the total unbalance amounts m1H-m2H. In this comparison, m1H−m2H<m1H
In other words, if m1H−m2H≠m1H,
The process control circuit 12 selects curve 2 by shifting the characteristic curves stored in the memory circuit 10 by one characteristic curve in the direction that increases the amount of imbalance with respect to the pickup output. In addition, m1H-
When m2H=m1H, m2H=0 and the added weight m1H is equal to the wheel unbalance amount X, so the display circuit 13 displays this value. The selection circuit 11 reads out the unbalance amount m12 corresponding to the pick-up value Y2 and the unbalance amount m22 corresponding to the pick-up value Y2 in the characteristic curve #2 from the storage circuit 10 and outputs them to the discrimination circuit 14.

By the way, there is a difference between the total unbalance X in the first measurement with no weight added and the total unbalance X-m1H of the wheel in the second measurement with the weight added, which is only the weight m1H. There is a change in the unbalance amount. Therefore, the fact that the difference m12-m22 between the unbalance amounts m12 and m22 in the characteristic curve #2 corresponding to the pickup outputs Y1 and Y2 calculated by the discrimination circuit 14 and the weight of the added weight is equal to This means that a characteristic curve that matches the measurement conditions has been selected.

In this way, when the characteristic curve #2 that matches the current measurement conditions is specified, the selection circuit 11 determines the unbalance amount m12 corresponding to the pickup output value Y1 on the characteristic curve #2. This is displayed by the display circuit 13 as the power unbalance amount.

Hereinafter, while sequentially replacing the characteristic curves in this way, the two values Y1 and _Y2 from Pickup 3 will be
Read out the unbalance amounts m1n and m2n that match, and select one of the optimal characteristic curves by sequentially moving the characteristic curves until the difference m1n - m2n in the unbalance amounts becomes equal to the known added weight. go.

In the above embodiment, in order to simplify the explanation, the case where the added weight and the total amount of unbalance from the measuring device completely match was used as an example. However, in practical terms, 3g Since an error of about 5g to 5g is allowed, no inconvenience will occur even if it is determined that the desired characteristic curve has been selected when the error falls within the range of 3 to 5g.

Furthermore, in this embodiment, five types of characteristic curves, H, #2 to #4, and L, are to be stored in the memory circuit, but the number of characteristic curves to be stored depends on the required measurement accuracy. It may be determined as appropriate.

In the above-described embodiment, the amount of unbalance is displayed, but the difference between the weight and the initially added weight may be displayed.

(Effects of the Invention) As explained above, in the present invention, the wheel stores a plurality of characteristic curves corresponding to different vehicle types, indicating the relationship between the magnitude of vibration generated during wheel rotation and the correct amount of unbalance. while selecting a characteristic curve in which the difference in unbalance amount corresponding to the pickup output before and after adding the known amount of weight specified by one of the characteristic curves matches the weight of the added weight. As a result, regardless of the type of wheel, the type of vehicle on which the wheel is installed, or the state in which the pickup is installed, it is possible to reduce the amount of unbalance of the wheel while it is still attached to the vehicle by a single weight addition action. Accurate measurements can be made, and the time and effort required for balancing automobile wheels can be significantly reduced.

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[Brief explanation of the drawing]

FIG. 1 is a block diagram of a device showing an embodiment of the present invention, and FIGS. 2 to 4 are lines showing the relationship between pick-up output and unbalance amount in an on-the-car type unbalance measuring device, respectively. 5 is a diagram showing the data contents of the memory circuit in the above device, and FIG. 6 is an explanatory diagram showing the operation of the same device. 1...Wheel, 2...Axle, 3...Pickup, 4...
Drive wheel, 5... Electric motor, 6... Flash lamp, 7
...Flash drive circuit, 8...Amplification circuit, 9...Analog-digital exchange circuit, 10...Memory circuit, 11...
Selection circuit, 12...Process control circuit, 13...Display circuit. 〓〓〓〓

Claims (1)

[Scope of Claims] 1. A first step of measuring the magnitude of vibrations occurring during rotation of wheels mounted on a vehicle, and measuring the magnitude and unbalance of vibrations occurring during rotation of wheels mounted on various vehicles. From among the plurality of characteristic curves obtained by examining the relationship between the A second step of determining the total amount of rough unbalance corresponding to the size, a third step of adding a weight corresponding to the total amount of rough unbalance, and a third step of determining the amount of vibration that occurs during rotation of the wheel to which this weight is attached. a fourth step of measuring the vibration magnitude; a fifth step of determining an arbitrary one from among the plurality of characteristic curves to determine the amount of unbalance corresponding to the magnitude of the vibration in the fourth step; The unbalance amount obtained in the process and the first one obtained by specifying any one from among the plurality of characteristic curves.
A sixth step in which the difference between the unbalance amount corresponding to the sameness of vibration in the process is added in the third step to select a characteristic curve that matches the weight of the weight, and a characteristic curve selected in the sixth step. An on-the-car type unbalance measurement method comprising a seventh step of determining a total unbalance corresponding to the magnitude of vibration in the first step based on the curve. 2. Storage means for storing a plurality of characteristic curves obtained by previously investigating the relationship between the magnitude of vibration generated during rotation of wheels mounted on various vehicles and the amount of unbalance;
pick-up means for detecting the magnitude of vibrations occurring during rotation of the wheel to be measured; calculation means for calculating the unbalance amount from the characteristic curve of the storage means based on the pick-up output; based on the same characteristic curve by the two pick-up outputs; a discriminating means for detecting a difference in the amount of unbalance; a first pick-up without adding any weight; A total unbalance amount corresponding to the output is outputted from the calculation means, and when a weight having a weight corresponding to this total unbalance amount is attached, the second
process control means for inputting the pick-up output and the first pick-up output to the discrimination means and sequentially reading out the characteristic curves in the storage means until the output thereof matches the unbalance amount corresponding to the added weight; , and display means for outputting the unbalance amount based on the selected characteristic curve and the first pickup output.